Process of mixing and burning fuel



March 10, 1936. R L, SCOTT 2,033,155

PROCESS OF MIXING AND BURNING FUEL Filed 001,. 25, 1950 Patented Mar.10, 1936 UNITED STATES PATENT OFFICE rnocsss, or mxmc arm mmme FUEL-Philip Lane Scott, s... Mateo, Calif.

Application October 25, 1930, Serial No. 491,18 7cm; (01.123-33) Myinvention relates to certain new and useful improvements in internalcombustion engines, which are described as follows:

The invention relates particularly to the method of preparing -afuel-air charge for combustion in an internal combustion engine inwhich' fuel is introduced into a rapidly moving air current caused bypassage of a part of the air charge back and forth between the maincylinder and an auxiliary chamber promoting an intimate mixture betweenthe air and fuel, the time of ignition and the subsequent rate ofburning being under control, as well as the compression and rate ofpassage of air and fuel into and between the chambers. The inventionrelates particularly to engines having the conventional cylinder andpiston and using a relatively non-volatile oil as fuel.

For convenience the system is shown diagrammatically, applied to atwo-stroke cycle engine of conventional form, using heavy oil as fuel,but it is to be understood thatit may be applied to a wide variety ofengine forms and to the use of many different fuels.

My invention is illustrated more or less diagrammatically in theaccompanying drawing, wherein- Figure 1 is a vertical cross sectionthrough an engine;

Figure 2 is a detailed section on an enlarged scale, illustrating aportion of the fuel feeding mechanism.

Like parts are designated by like characters throughout thespecification and drawing.

A is an engine cylinder with a main combustion space A B is a pistontherein. C is a connecting rod joining the piston to the crank shaft D.E is a housing or crank case. F is the port through which burnt gasesare exhausted and F is the port through which air is forced by any wellknown means for the clearing of burnt gas and the recharging of thecylinder.

G is a mixer head, provided with a cooling jacket G whichmay be omitted,having a close fitting piston G slidably mounted in the barrel GConnecting this barrel or mixing space G with the combustion space A isa throat G into which opens the fuel atomizing port J supplied through acanal J in the body. J is a fuel inlet supplying this system with fuel,which may be under pressure, as from a pump or other pressure source.The fuel inlet passage J is shown as formed partially by means of anannularchannel J cut in the bottom of the mixer head G and as beingcompleted by the head J provided with an annular channel J. The member Jis so formed that on the inner side it does not contact the bottom ofthe member G and thus a suflicient clearance is provided to form thefuel atomizing port J As shown this is an annular port ex- 5 tendingentirely about the throat G It might, however, be of any suitable formand need not be continuous. In place of the fuel discharge arrangementshown, any suitable atomizing valve might be used to supply fuel to themixing cham- 10 her. On the upper end of the piston G is mounted aroller Ci which is driven by a cam H, imparting axial motion to thepiston. This cam is rotated by means of a shaft H upon which is a gearH, meshing with a gear 1-! on a shaft H 15 driven by the engine. Thisdrive is not shown in complete detail and may be ofany suitable nature.

I is a spark plug or ignition device which may be used. For somepurposes such an ignition de- 20 vice is desirable. For other purposesit is not and it is not an essential part of my invention.

It will be realized that whereas I have herewith shown and described apractical operative device, nevertheless many changes might be made 25in the size, shape, number and disposition of parts without departingfrom the spirit of my invention, and, therefore, I wish my showing to betaken as in a sense diagrammatic.

Particularly, the auxiliary or compression cylo inder might be uncooled.The cooling jacket G would thus be omitted.

The method of operation of my invention is as follows:

In the position of the parts shown in the figure, 5

it is assumed that the exhaust has taken place and a fresh charge of airhas been segregated or trapped in the cylinder. This charge is beingcompressed. At some point in the compression stroke, the piston G in themixing chamber is 40 permitted to recede by the cam, being forced backby the pressure in the main chamber. The piston might be positivelyoperated by any suitable mechanism, timed to cause its withdrawal at theappropriate period in the engine cycle. 45 During this phase, fuel isfed into the moving air steam. The fuel may thus be fed through one ormore discharge openings appropriately placed to act in conjunction withthe moving air currents. The speed of the motion of the air, its 50 dropin pressure and the resulting drop in temperature, is controlled partlyby the rate of motion of the piston (i and as to temperature, partly bythe degree of cooling applied to the chamber G The degree of atomizationof the 5g finally admitted to the mixing chamber, is controlled by theconstruction of the fuel admission orifice and by the air speed andpressure and temperature conditions just mentioned. The amount of air somixed with the fuel, in proportion to the total amount of air originallyentrapped within the main cylinder, is controlled by the size of themixing chamber and the amount of recession of the piston lying therein.The amount of fuel mixed with this quantity of air is controlled by thefuel feeding mechanism. The proportion of air to fuel in this chambermay then be varied through a wide range. permitting mixtures all the wayfrom too lean for combustion through combustible ratios to and includingtoo rich for combustion. For the p rpose of this description theexpressions lean mixture", "rich mixture" or combustible mixture aretaken from the terminology commonly used in describing carburetingengines in referring to fuel air ratios, although in this case the fuelmay not be, especially if the oils are relatively non-volatile, in atruly dry gas condition, as they are supposed to be in considering thecarbureting engine.

This fuel air mixture in the chamber G is then discharged into the mainchamber A at a predetermined point in the engine cycle, inflammationoccurring as the result of an increase in pressure due to evacuation ofthe chamber G or to further motion of the piston B or a combination ofthe two. It is also possible to cause initial inflammation by someauxiliary means, such as a spark or a hot wire. This discharging of thefuel air mixture further promotes mixing and atomization and furtherfuel may be added during this phase, providing further means forcontrolling the combustion process to secure the maximum release ofenergy in a given size of chamber. Depending on the condition of themixture in the chamber and the temperature and pressure conditionsprevailing, inflammation will occur either in the chamber G or in thechamber A or in both, and may also be influenced by the motion of thepiston G The outward rush of the fuel air mixture from the mixingchamber into the charge of pure air promotes intimate mixing betweenthis initial fuel air charge and the remaining air, for the purpose ofsecuring complete combustion.

It is possible that conditions may make it desirable to have theevacuating stroke of the piston in the mixing chamber occur at or afterthe upward dead center position of the piston in the main cylinder.

I claim:

1. The method of mixing fuel and air for combustion in an internalcombustion engine, which consists in compressing a body of air in a maincylinder, creating a current of air under pressure by moving asubstantial portion of said compressed air to an auxiliary chamber incommunication with the main cylinder, said current of air being timedand controlled independent of the compression of the air in the maincylinder, feeding fuel under substantial pressure to said current of airand igniting the fuel and air.

'2. The method of mixing substantially all the fuel and air charge forcombustion in an internal combustion, which consists in compressing abody of air in a main cylinder, creating a current of air under pressureby moving a substantial portion of said compressed air to an auxiliarychamber in communication with the main cylinder, said current of airbeing timed and controlled independent of the compression of the air inthe main cylinder, feeding fuel under substantial pressure to saidcurrent of air and igniting the fuel and air.

'3. The method of mixing within a confined space fuel and air forcombustion in an internal combustion engine, which consists incompressing a bodyof air in a mainoylinder, creating a current of airunder pressure by moving a substantial portion of said compressed airfrom the main cylinder to an auxiliarychamber through a relativelynon-turbulent passage of substantial area, said current of air beingtimed and controlled independent of the compression of the air in themain cylinder, feeding fuel under substantial pressure to'said currentof air and igniting the fuel and air.

4. The method of mixing within a confined ,space substantially all thefuel and air charge for combustion in an internal combustion engine,which consists in compressing a body of air in a main cylinder, creatinga current of air under pressure by moving a substantial portion of saidcompressed air to an auxiliary chamber in communication with the maincylinder, said current of air being controlled and timed independent ofthe compression of the air in the inain cylinder, feeding fuel undersubstantial pressure to said current of air and igniting the fuel andair.

5. The method of mixing a liquid fuel charge with air and burning theresulting mixture, which comprises compressing the body of air in achamber, setting up a rapidly moving current of air between said chamberand a communicating chamber, supplying liquid fuel to said current ofair at its point of maximum velocity and igniting the mixture, saidcurrent of air being timed and controlled independent of the compressionof the air in said first mentioned chamber.

6.-The method of mixing a liquid fuel charge with air and burning theresulting mixture, which comprises compressing a body of air in a chamber, setting up a rapidly moving current of air between said chamber anda communicating chamber, supplying liquid fuel to said current of air atits point of maximum velocity, and igniting the mixture by the heat ofcompression, said current of air being timed and controlled independentof the compression of the air in said first mentioned chamber.

7. The method of mixing a liquid fuel charge compression of the air insaid first mentionedchamber.

PHILIP LANE SCOTT.

